This invention relates to a vehicle driven by a linear motor. The vehicle--also termed as magnetic levitation or "maglev" train--forms the armature of the linear motor and carries on its chassis permanent magnets which cooperate with longitudinal stators arranged along the travel path to generate magnetic travelling fields which drive and at least partially support the vehicle. The vehicle has upper and lower guide rollers for maintaining an air gap of a predetermined order of magnitude between the vehicle-mounted magnets and the longitudinal stators. Such a vehicle is disclosed, for example, in German Offenlegungsschrift (application published without examination) No. 31 07 341. For regulating the magnetic force to adapt it to various operational conditions, the air gap between the longitudinal stators on the one hand and the permanent magnets, on the other hand, is set mechanically by means of springs and levers. Position-defining devices are constituted by guide rollers. It is a disadvantage of this conventional mechanical air gap regulation that it has an appreciable hysteresis which in certain operational conditions may result in an overloading of the guide rollers. It is a further drawback that the assembly and the maintenance work of such a lever system are labor intensive and thus expensive.
Further, German Offenlegungsschrift 29 33 451 discloses the use of electromagnets and, in case of peak loads, the additional use of wheels with a lever system to maintain spacing and to support the vehicle load. It is a disadvantage of this arrangement that the electromagnets have a high electrical energy consumption and the assembly and maintenance work for the lever system of the additional wheels is complex.